The present disclosure relates to an embedded multilayer ceramic electronic component and a printed circuit board having the same.
In accordance with high density and high integration of electronic circuits, a mounting space for passive devices mounted on printed circuit boards has been insufficient. In order to solve this problem, an effort for implementing components embedded in the boards, for example, embedded devices have been conducted. Particularly, methods of embedding multilayer ceramic electronic components used as capacitive components in boards have been variously suggested.
As the method of embedding the multilayer ceramic electronic component in the board, there is a method of using a material of the board itself as a dielectric material for a multilayer ceramic electronic component and using a copper wiring, or the like, as an electrode for the multilayer ceramic electronic component. In addition, as another method of implementing an embedded multilayer ceramic electronic component, there are a method of forming a high-k polymer sheet or a dielectric thin film in the board to form the embedded multilayer ceramic electronic component, a method of embedding the multilayer ceramic electronic component in the board, and the like.
Generally, multilayer ceramic electronic components include a plurality of dielectric layers formed of a ceramic material and internal electrodes inserted between the plurality of dielectric layers. The multilayer ceramic electronic components as described above are disposed in boards, such that the embedded multilayer ceramic electronic components having high capacitance may be implemented.
In order to manufacture printed circuit boards having embedded multilayer ceramic electronic components therein, after inserting the multilayer ceramic electronic components in core boards, via holes should be punched in upper and lower multilayer plates using a laser beam in order to connect board wirings and external electrodes of the multilayer ceramic electronic components. This laser processing may be a cause of significantly increasing manufacturing costs of printed circuit boards.
Meanwhile, since the embedded multilayer ceramic electronic components should be embedded in a core portion in the boards, nickel/tin (Ni/Sn) plating layers are not required to be formed on the external electrodes, unlike general multilayer ceramic electronic components mounted on board surfaces.
For example, since the external electrode of the embedded multilayer ceramic electronic component is electrically connected to a circuit in the board through a via formed of copper (Cu), a copper (Cu) layer should be formed on the external electrode instead of forming the nickel/tin (Ni/Sn) plating layer thereon.
Generally, although external electrodes may contain copper (Cu) as a main ingredient, but glass is also contained therein, at the time of performing a laser process for forming vias in boards, ingredients contained in the glass absorb the laser beam, such that forming depths of vias may not be able to be controlled.
Therefore, copper (Cu) plating layers are separately formed on the external electrodes of the embedded multilayer ceramic electronic components.
Meanwhile, generally, external electrodes of on external electrodes in embedded multilayer ceramic electronic components are formed by applying a conductive paste for an external electrode to both end portions of ceramic bodies.
In this case, application shapes of external electrodes are not uniform, and shapes of external electrodes formed on both end surfaces of ceramic bodies are not flat, such that it may be difficult to sufficiently secure widths of the external electrodes formed on upper and lower surfaces of the ceramic bodies.
In addition, since the application shapes of the external electrodes are not uniform, it may be difficult to control thicknesses in respective regions, such that at the time of embedding the embedded multilayer ceramic electronic components in the boards, delamination defects between the embedded multilayer ceramic electronic components and the boards may occur due to deviation in the thicknesses of the external electrodes, causing deteriorate reliability.